Temperature regulator



Oct. 7, 1924] E. F. COLLINS ET AL TEMPERATURE REGULATOR Filed Feb. 20. 1922 w M WWW M o yfi m ,fi Ma r m m. m. En.

m/ a b I Patented Oct. 7, 1924.

UNITED STATES 1,511,050 PATENT OFFICE.-

N. OTIS, OF SCHENECTADY, NEW YORK, ASSIGNORS COMPANY, A CORPORATION OF NEW YORK.

TEMPERATURE REGULATOR.

Application filed February 20, 1922. Serial No. 537,884.

To all whom it may concern:

Be it known that we, EDGAR F. Connms and ALBERT N. (has, citizens of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Temperature Re' ulators, of which the following is a specification.

Our invention relates to temperature regulators for electrically heated apparatus, such as for electric furnaces and the like, and has for its object the provision of improved means for throwing the heating load on and off the ower supply circuit in response to changes in temperature.

In the operation of electric furnaces rcquiring a considerable amount of power, such as furnaces for hardening and drawing metallic articles, considerable difiiculty may be experienced with the usual type of temperature regulating system in which the temperature .is regulated by throwing on and off portions of the heating load, and in which there is a possibility of a number of portions being thrown on or ofl" at one time. Such a condition may arise also in case a number of separate furnaces are connected to the same supply source. The

. intervals of throwing on or off of a considerable amount of heating load results in shocks on the electric generating equ; ment and causes various other undesira e characteristics, such as fluctuations 111 the voltage of the electric supply circuit.

In carrying out our invention we arrange the temperature responsive control in such a way that only one portion of the total heating load can be thrown on or off the supply, circuit at one time. In this manner shocks on the generating equipment are avoided. In-one embodiment of our invention we provide a selector switch which is continuously rotated and adapted to connect the temperature responsive control means in operative relation with the portions of the heating load successively so that the portions'may be separately thrown on or off the power circuit. with appreciable time between, whereby the generating equipment is given an'opportunity to adjust itself to each change in load.

For a more complete understanding of "ourinvent ion referenceshould be had to o the accompanying figure of drawing in the single which is shown in diagrammatic 'heaters 12 to 16, inclusive,

form a system of control for electric furnaces embodying our invention.

Referring to the drawing, we have shown our invention in one form as applied to the control of two electric furnaces 10 and 11 which may be independent furnaces or a group of furnaces, through which the charge or work may be conveyed in succession. These furnaces may be maintained at the same temperature or at different tem peratures as desired and, obviously, one furnace only or more than two furnaces may be used. The furnace 10 is provided with three electric heaters 12, 13 and 14, while furnace 11 is provided with two heat-' ers 15 and 16. The heaters may be of the resistance type and are each shown as consisting of three resistance elements con nected in a a connection for operation on a three-phase source of electrical supply 17. Within the meaning of our invention, the electric heaters instead of being grouped in one or more furnaces may each be located in a separate furnace. r

,The connection of each of the resistance with the supply "source 17 is effected through control devices 18 to 22 inclusive of a well known type disclosed in U. S. patent to Edgar F. Collins, No. 1,391,996, dated September 27, 1921. Control device 18, only, has been shown in detail, but it will be understoodt-hat con trol devices 19 to 22 inclusive are similar to control device 18. Control device 18 comprises a switch 25 for connecting and. disconnecting resistance a 12 to the supply source 17. This switch is actuated by an operating coil 26, the energization of which is controlled by means of a relay 27 which is adapted, to be thrown to one or the other of two circuit'closing positions by means of operating coils 28 and 29. When thrown to the position shown in the drawing upon the energization of coil 28, con-,

tact arm 30 of the relay bridges a pair of for example, disclosed iii govern. J'hefl cosriying on elec rice ly comhaclmg i: och e col; tee-t are ormnge u circle buying il's center Swilch 37 comprises on operating:

. lower and insulated arms and ll) uilepeil 2'0 cooperate Wieh pairs or evinmeiricelly l L stationary conpeirs of conaround the peri i'ihery of the shaft; 3?.

each giioir i? co'imcts lying in a radius of this circle. ly m; o

iuilsahlo slow speecl by Shaft is rote-ted continuousmeens of :1

consie-m speed ilriving; means, such as on electric motor 51, and

thus moves contact arms 39 and co successively over the pairs of stationery contocis.

moio ever the statione y contecis,

he observed that the opposite sleiionary connected momentarily he hhe contact owns it will er diuinetrically cone-aces are electrically by arm 39, While the inner diametricall onosite steizioner contacts oreelectrically conneclecl moinenl, ly by sielimiury contacts ll.

eouoec'leii respectively coils The inner contacts of re electrically connect Contact arm lhe of control glow ices pmrs 4G to ll"? inclusive r pairs 0% to inclusive ore to the relay opera? 18 to 22 inclusive.

oil to eloiionzu'y con" eel, 55 of temper- Lime responsive rlevice 1-35.

iihe outer contecis of these pairs to sizitionany contact 5c of lhe lemmreturo responsive device. the iuncll contacts of pairs l9 and to st etionory con-loot 57 responsive device 3'6; and the outer contacts of these pairs to stationary contact 1'38. ll:

will thus he 3% mid lll are rotated, coils of lhe 22 inclusive will he resistance control ohscrveil that Contact arms the relay operating so to he subject to control lay tin'iiperelure responsive devices previously described.

F and in the relation in one form of our invention chemo couples 30 to (34 inclus ore provided respeciively for the sections of the furnaces heated by resistances 12 lo 16 inclusive. lhe

electr telly conneo ierminals of which are to stationary contacts svninu'elirically arrengei'i gielal'ier with similar poi techs 7% to 74- inc? we're '70 to 72- inclu i T5 of ovitog element 35 to (39, inclusive. eroiuul shaft 38 Lors oi slotiono'ry con.- The pairs of conconnecterl so "l/hc -i;empereture reopen sive device While the eirs of contacts P i, i 1

8 to Hi inclusive are connected to she movmg element 76 of temperature responsive device 36.

0011mm; mine en the upper coil, o2:

1 3.. by too soce Contract arms 80 and 81 simileir 0 1071115 c ng edi to so m b eseiyeli' engag per-attire responsive of temgeretinre devices 18 locounecteil successively successive connection '01 spaced contacts to Y4: inclusive. In

couples 50, G1 and 62 are momentarily end perioziicolly connected by contact arms 8% and 81 to the im'iving element of term device 35, While thermocouples l3 and 61 are momentarily and periodically comioc'lied to moving element 76 of icinperature responsive device Switch. 37 thus arranged. lo connect one or the other of the temperature responsive devices 35 and S6 to both the thermocouple and the relay operating coilscorresponding lo any particular resistance heater at the some time. For example, as shown in the drawing, thermocouple 60 is connected to moving element 75 at the some time that stationery contacts 55 and 56 are connected to operating coils 2S and 29 of relay 27.

thus constructed and arranged. the pemtion of our invent-ion is as follows: he temperetuue responsive devices 35 and may he set maintain the same temeroture or clili erent temperatures as defrecl. Whci'i the furnace sections creeperting at the preoi-zliermincd mean working temperature. l'he poini'ers carried by movillelei'nents 77 and 76, as the ten'iperaturi'a couples. will he moved to positions between their respeetiw siotionziry contacts 55, 56 Hllll 5T. 58. as shown in the drawing, and will therefore not he pinched loy their re i-ipeillll'vli reciprocating contacts 853 and 83. shown as driven by elec bric motors 89' and 83. to close the relay control circuits. None of the relays will therefore he 0pcro'fiod under these conditions. Upon a rise oi 'ten'iperuture in any one of the sections loithe predetermined maximum value, the pointer ('ttlllP-Ll by the corresponding moving element 75 or 76, as the case may he. will he pinched bet-Ween. contacts 32. 5G or 83, 58. .When switch 37, for example, reaches the position shown in the drawing. should the section of the fm'nooe heated by resislonce 12 be u'o'the pi-eiletormium. musiinum temperature the leinperutm'o rcspmrsire device will close a circuit for openoiing mil 29 of relay 27. throwing: the relay to its opposite position whereby arm 30 opens lihe circuit For coil and also for coil Switch thereupon drops out. disconnecting resistance 12 from the supply source, H be temperature of the furnace sections healed by resistance heaters 13 and ll should also have increased to the predetermined maximum temperature, t ey will be similarly disconnected individually through control devices 19 one 20 upon the thereto of temperature responsive device as selector switch 37 rom'izes. In summer resistances 15 and control relay will nation with or a source of I g'ovisions of, the patent statutes, it should ennon 16 will be disconnected b temperature re sponsive device 36. As tie temperature or" any furnace section decreases now and reaches the predetermir misiinum value, then pointer or 76 w l he pinched be tween contacts 82,

be thrown back to the position shown in the drawing, again connecting the corresponding resistance to the supply circuit. The heaters are thus coutrolled so as to maintain a predetermined mean Working temperature in each of the furnaces.

It will be observed thatshould ouch scrtion of the furnace he provided with temperature control means, it would be possible in case several orall of the sections should reach the predetermined maximum or minimum temperatureat the same time for a number of heaters to be thrown on or oil" together, which would cause a shock to the power supply system as previously pointed out. With our invention, however, it is impossible for more than one portion of the heating load to be thrown. on or oil at one time.

While We have described our invention as embodied in. concrete form and o 'icrating in a specific manner in accordance with .t'hc

understood that we do, not limit our invention thereto, since various modifications thereOI will suggest themselves to tlioso skilled in the without departing from the spirit of our invention, the scope of which is set forth in the annexed claims.

at we claim as new and desire to so cure by Letters Patent of the United States, is:- v

1. In a temperature regulator, the combia lurality ofelectric heaters, electrical supply for said heaters, and temperature responsive control means for connecting said heaters to said supply source separately at intervals upon the occurrence of a predetermined minimum temperature and for disconnectingsaid heaters separately at intervals upon the or, currence of a predetermined maximum tomperature. q

2. In a temperature regulator, the combination with a'plurality of electric heaters. of a temperature responsive control dcvicv, and selective means for periodically (01% controlling necting said control device to operate in 55 in a temperature regulator, the com- 69 hination with a plurality of electric heaters, a control device for each of said heaters, temperature responsive means. and selective switching" means for connecting said tcm-c pcrature responsive means to said control 55 devices in sequence whereby said heaters are imliridually controlled so as to maintain a. predetermined temperature.

4. In a temperature regulator, the combination with a plurality of electric heaters, 79

an electromagnetically actuated switch in the electrical supply circuit to each of said heaters, temperature responsive control device for said switches, and selective witching means for connectingsaid control 7 device to said switches in sequence, whereby said heaters are individually controlled to maintain a predetermined temperature.

5. In a. temperature regulator, the comb nation with plurality of elcctrioheatcrs, 30

relays for controlling: the electrical supply circuit to each of said heaters, temperature responsive means associated with each of said heaters, a relay control device actuated by said temperature responsive means, and

sclcctiyc switching means for electrically coruuctlng said control device to the tempcraturc responsive means and the relay of each of said heaters in sequence.

6. in a 'tem erature re ulator, the romhi- 99 nation with a plurality of electric heaters, thermocouples associated with said heaters,

independently operable switches in the circuits of said heaters, electromagnetic means for controlling; the opening and closing oi said switches, a circuit controlling dcvi'cc arranged to be controlled by said thermocouples, and continuously operating selcctivc switching means for connecting the thermocouple and of caclrheater in sequence to" said circuit device whereby said heaters are scparatelycontrollcd to maintain a predetcrmined temperature.

In witness whereof, we have hereunto set I 195 our hands this 19th day of February, 1 22.

EDGAR F. CULLlNS.

ALBERT OTIS.

switch controlling means 100 

